1. Field of Endeavor
The present invention relates to chemical and biochemical synthesis and more particularly to the use of carbonates for chemical and biochemical synthesis.
2. State of Technology
Autotrophic, aquatic organisms are commonly cultured to produce a range of products including food, feed, and chemical feedstocks. Considerable interest has also recently focused on the mass culture of such organisms for the direct or indirect production of fuels (biofuels). Because the preceding organisms usually synthesize organic compounds from inorganic carbon dissolved in the growth media, an adequate source of such carbon is critical for space- and volume-efficient biological production of end products. The internal biological demand for inorganic carbon can outstrip that which can be supplied via simple air equilibration with the media. This is commonly rectified by elevating the dissolved inorganic concentration in the media via equilibration with gas containing elevated CO2 and/or the addition of synthetic, soluble carbon salts such as sodium carbonate or bicarbonate. Sources of concentrated CO2 gas include commercial tank gas, CO2 gas generators, and waste CO2, in most cases derived from the combustion of fossil fuels. Use of such CO2 sources therefore make the resulting biofuels dependent on fossil fuels, defeating one of the primary rationales for biofuel production. Furthermore, bubbling of gas into a solution is a relatively inefficient way of producing dissolved inorganic carbon, which can result in the loss of significant quantities of undissolved CO2 to air. The use of commercially produced carbon salts, in particular sodium carbonate or bicarbonate, as a carbon source must be limited because of their relatively high production cost and fossil carbon footprint.